Document Type : Full Research Paper

Authors

• Hosein Ghasemi ¹
• Mohammad Saeid Saeidi ²
• Bahar Firoozabadi ²

¹ M.Sc, Mechanical Engineering Department, Faculty of Mechanicacal Engineering, Sharif University of Technology

² professor, Mechanical Engineering Department, Faculty of Mechanicacal Engineering, Sharif University of Technology

Abstract

Knowledge regarding particle deposition processes in the pulmonary system is important in aerosol therapy and inhalation toxicology applications. The present work describes a computational model of human lung airway consisting of the three-generation pathway from the trachea down to segmental bronchi. In order to more appropriately model human air passage, an asymmetric geometry (i.e. three generation airway) is extracted from the 1th to 3th branches of the Hoursfield model and on dealing with the complexities of simulations (e.g. computation time) structured mesh is developed which also leads to more accurate computations. The fully three-dimensional incompressible laminar Navier– Stokes equations and continuity equation have been solved using CFD home code on generated mesh. Computations are carried out in the Reynolds number range of 800–1800, corresponding to mouthair breathing rates ranging from 0.18 to 0.41 l/s, representative. The study leads to establishing relations for overall particle deposition efficiency in the second generation of bronchial tree as a function of two dimensionless groups of Reynolds and Stocks numbers. Furthermore, interpretation of correlations are enlightened the fact of that in the initial generations of bronchial trees, consideration of asymmetric geometry has a significant influence on the particle deposition pattern. The results of the paper are valuable in aerosol therapy and inhalation toxicology.

Keywords

• Lung Airway
• Horsfield model
• CFD
• Structured Mesh
• particle deposition
• Fluent

Main Subjects

• Biological Computer Modeling / Biological Computer Simulation